An earthquake that occurred approximately 30 miles underground and registered 6.8 on the Richter Scale shook the Earth's surface for about 30 seconds near Olympia, Washington on February 28, 2001. A pendulum that makes tracings in sand was sitting in a shop in Port Townsend, Washington and traced this pretty, rose-shaped design in the sand during the 'quake.
Read more about the "earthquake rose" at the photographer's website.